- Implantation bleeding is a normal, early sign of pregnancy and typically lighter than your period.
- Implantation bleeding will usually be pink or light brown and have a thin, watery consistency.
- It's possible to experience implantation bleeding around the same time as you would your period.
- Visit Insider's Health Reference library for more advice.
After conception, when the sperm cell joins with the egg, the fertilized egg moves down the fallopian tube to the uterus and attaches to the uterine lining. This is called implantation, and it can cause light bleeding or spotting, but not every woman will experience it during pregnancy.
Implantation bleeding is normal and usually doesn't indicate a problem, according to the American College of Obstetricians and Gynecologists. But you might not know whether it is your period or implantation bleeding. Here's how to tell the difference.
When does implantation bleeding occur?
Implantation bleeding occurs about 10 to 14 days after conception. Because that's usually around the same time you would normally have a period, you might confuse implantation bleeding with a light period.
For women who are trying to get pregnant, they might think, "This isn't my normal period. I should take a pregnancy test," says Melody Baldwin, an OB-GYN at Duke Health. But for women who don't have pregnancy on their radar, they might just think their period was lighter than usual, she says.
How long does implantation bleeding last?
Implantation bleeding typically lasts a couple of days, and "it's generally less heavy, shorter, and less painful than a typical period would be," Baldwin says.
When the fertilized egg implants in the uterus, it disrupts part of the uterine lining, and that causes the bleeding, Baldwin says.
The resulting bleeding is small because the embryo is small at that point, and it disrupts only one area of the uterine lining, she says.
By comparison, during your period, the blood comes from the uterus shedding its lining. That creates a heavier flow than the disruption to the uterine lining during implantation.
There does not seem to be a difference in implantation bleeding based on whether the woman has been pregnant before, says Leena Nathan, an OB-GYN at UCLA Health Westlake Village.
Is it implantation bleeding or my period?
The key difference between implantation bleeding and your period is that implantation bleeding flow is typically lighter and lasts only a couple of days.
However, if you usually have a light period to begin with, it may be difficult to distinguish between the two.
Some other signs to look for are early pregnancy symptoms, Nathan says. These may include:
- Breast tenderness
- Bloating
- Fatigue
- Nausea
- Mild cramping
If you have cramping with implantation bleeding, it would be less intense than typical period cramping, Baldwin says.
Also, for some women, implantation bleeding may be a different color, like brown or pink, rather than the typical red you'll see from your period. It also usually doesn't involve clotting, Nathan says.
The best way to know if it's implantation bleeding is to take a pregnancy test.
"Most of the pregnancy tests that are commercially available now would detect a pregnancy around the time of a missed period, which is about the time that implantation bleeding occurs," Baldwin says.
If you have bleeding and take a test that is negative, Nathan recommends repeating the test in a few days.
Implantation bleeding is fairly common. "It's something that we see relatively often. We field a lot of phone calls about it," Baldwin says.
Insider's takeaway
Although implantation bleeding doesn't usually require medical attention, there are some exceptions.
For patients who don't have any pregnancy complications, implantation bleeding is usually nothing to worry about, Baldwin says. But If you are unsure about what's going on, it's probably a good idea to call your OB-GYN.
"What I always feel bad about is when I have a patient that says 'I didn't know if I was worrying too much, and I didn't want to call and bother you,'" Baldwin says. "Patients can always call and clarify this with us, because that would give us the opportunity to take care of something that might not be typical or normal. And then it also gives us the opportunity to reassure them," so they don't keep worrying until their next appointment, she says.